1. Field of the Invention
The present invention is in the field of treating calcareous bonding agents, particularly cement, involving the calcining of finely grained solids, the latter being conveyed by means of hot gases through a preheating and calcining zone, and subsequently into a rotary kiln where the solid matter separated from the hot gases is converted into clinker. The clinker is then cooled and ground to a cement product. The present invention involves separating off a branch stream of the suspended solid particles and treating them in parallel with the rotary kiln to produce an airborne clinker.
2. Description of the Prior Art
It is well known that cement calcining systems are susceptible to a build-up of alkali and chlorine compounds during the internal circulation of the suspended materials in the calcining system. In order to effectively counteract the known difficulties resulting therefrom, particularly due to the deposition of incrustations, it has previously been proposed to remove from the primary gas circulation stream between the rotary kiln and the heat exchanger system, a partial stream, to cool the stream for condensation of the harmful substances, to deposit and dispose of the harmful substances in the form of dust, and to exhaust the remaining gas in a bypass.
This existing system leads to losses of heat energy in the discharged partial gas current, as well as losses of solids. An additional disadvantage is the fact that the elimination or the further utilization of the dust deposited in the bypass installation must be eliminated from the production process. The difficulties caused by such deposition are detailed in the publication "Zement-Kalk-Gips", Vol. 5, 1962, page 203.